Segmented Nut for Screw Connections

ABSTRACT

A nut for screw connections has two substantially identically sized nut segments of a half-shell shape, wherein the nut segments each have an inner side provided with an inner thread segment defining together an inner thread. The nut segments are connected to each other so as to be moveable toward each other until the nut segments reach a closed position. The nut segments are maintained in the closed position by springs or a locking device. An actuating device is moveably arranged on at least one of the two nut segments for releasing the closed position, wherein the actuating device is adapted to manually actuated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of application Ser. No.13/099,389 having a filing date of 3 May 2011 and claiming a prioritydate of 3 May 2010 based on prior filed German patent application No. 102010 016 758.4, the entire contents of the aforesaid U.S. applicationand the aforesaid German patent application being incorporated herein byreference.

BACKGROUND OF THE INVENTION

The invention relates to a nut for screw connections. The nut iscomprised of two substantially same-size half-shell screw segments thateach on their inner side are provided with inner thread segments and arearranged so as to be movable relative to each other until a closedposition is reached. Further, means are provided that maintain the nutsegments in closed position.

Segmented nuts for use on screws or threaded bolts are known in theprior art. U.S. 2008/0301926 A1 discloses in FIGS. 9C-9F a segmented nutof a total of three identical nut segments. They are embodied like jawsand can be actuated by actuating a rotary ring that is rotatable about acentral axis of the nut between an open position and a closed positionwherein the jaws carry out a radial movement. In the closed positioninner thread segments formed on the inner side of the screw segmentsengage the outer thread of matching size of a threaded bolt. In the openposition, the inner thread sections formed on the segments do not engagethe outer thread.

The segmented nut according to U.S. 2008/0301926 A1 is designed andconstructed especially for use in a hydraulic tensioning jack. For manyother applications in the field of plant and apparatus engineering thissegmented nut is however not suitable, particularly because of the driveaction by means of a rotary ring that is arranged coaxially to the nut.In practice, this is not suitable for many construction and engineeringsituations.

DE 1 991 256 discloses a nut for a screw connection with twosubstantially identically designed nut segments that are pivotablerelative to each other and, for this purpose, are pivotably connectedwith each other at a first end area. For a positive fit (form fit) withthe thread of a threaded rod, the nut, with the nut segments in openposition, is first pushed onto the thread of the rod as far as possibleand the nut segments are closed. Subsequently, the nut is screwed byseveral turns so that a cylindrically designed longitudinal section ofthe nut reaches a receptacle in the form of a blind bore; opening of thenut segments from this point on is not possible anymore. The receptaclein the form of a blind bore serves as a closure means that preventsopening of the segments. The disadvantage is that only by a screwingaction of several turns a closure of the nut is achieved.

DE 83 08 905 U1 discloses a nut that is suitable for a quick adjustmentin axial direction. It is comprised of a housing comprising a ring thatcan be deflected against a spring force. This ring is provided on one ofits inner halves with a thread structure. A pressure spring loads thering in radial direction so that a positive fit (form fit) of the threadstructure with the outer thread of the threaded bolt results. Foropening, i.e., releasing the thread engagement, a pivotable lever isprovided that is supported in the housing so as to pivot about a pivotaxis that is arranged at a right angle to the screw axis. The actuationof the lever leads to a radial, i.e., lateral, displacement of the ringand release of the thread engagement.

The invention has the object to provide a segmented nut that is suitablefor many applications in plant and apparatus engineering and ischangeable very quickly between the closed position and the openposition.

SUMMARY OF THE INVENTION

In accordance with the present invention, this is achieved for asegmented nut of the aforementioned kind in that on at least one of thetwo segments an actuation device is movably arranged that is engageableby hand for releasing the closed position.

The two segments or jaws of the segmented nut are moved relative to eachother in parallel alignment so that already after short travel from theclosed position into the open position a separation of the inner threadsegments from the matching outer thread can be achieved. In practice,such a segmented nut can be operated especially quickly and simply,i.e., by means of a single actuation action. An important practicalapplication are, for example, flange screw connections on housings orfoundations of wind power devices. The fastening flanges employed inthese devices are provided about the circumference with screwconnections that are closely positioned relative to each other so thatbetween the individual screw connections, but also inwardly toward thehousing or foundation, there is only little space available. Only inoutward direction, the screw connection is freely accessible andtherefore provides here a certain accessibility in order to transfer thenut by means of the actuation device provided thereat from the closedposition into the open position.

Advantageous embodiments of the nut according to the invention aredisclosed in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWING

Embodiments of the invention will be explained in the following withreference to the Figures.

FIG. 1 is a perspective illustration of a first embodiment of a nutcomprised of two nut segments wherein the nut is illustrated in the openstate.

FIG. 2 is a side view of the nut of FIG. 1.

FIG. 3 shows the nut in plan view wherein a detail in the interior ofthe nut segments is illustrated in a broken-away section.

FIG. 4 is an illustration, partially in section, of a second embodimentof a nut comprised of two nut segments wherein the nut is shown in theclosed position.

FIG. 5 is a section view of the nut along the section plane V-Vindicated in FIG. 4.

FIG. 6 is an illustration as in FIG. 4 but in the open position of thenut.

FIG. 7 is a section view as in FIG. 5 but in the open position of thenut.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The segmented nut illustrated in FIGS. 1 to 3, is comprised of two jawsor nut segments 1 a, 1 b that are movable in parallel away from eachother and toward each other. Each nut segment 1 a, 1 b has approximatelya 180 degree circumferential extension. Separation or opening of thesegments 1 a, 1 b, as illustrated in FIGS. 1-3, effects opening of theinner thread segments 2 a, 2 b formed in the nut segments so that thenut opened in this way can be moved across a threaded bolt or a screw inaxial direction to a desired longitudinal position on the thread withouthaving to carry out a cumbersome screwing action across the entirelength of the thread of the threaded bolt or screw. On very longthreaded bolts the nut can therefore be positioned quickly at thedesired longitudinal position and then, by closing the two jaws, can besecured with positive fit on the threaded bolt.

Basically, two different embodiments are possible. In the firstembodiment the two inner thread segments 2 a, 2 b provide a completestandard inner thread when the nut is closed. Such a nut can thereforebe screwed just like any other nut when in its closed position.

In a second embodiment, the two inner thread segments 2 a, 2 b in theclosed position of the nut supplement each other to a clamping innerthread whose thread flanks clamp frictionally on matching threadedflanks of the threaded bolt or the screw. Such a nut cannot be rotatedin its closed position or only by application of very high torque on thecorresponding outer thread. The basic configuration of the nut is thesame in both embodiments.

The two segments 1 a, 1 b have semi-circular outer surfaces 4 and abuteach other in the closed position of the nut at a separation plane T(FIG. 3). When the nut is open, this separation plane T opens to aseparation gap of e.g. 5 mm to 10 mm.

For obtaining a parallel guiding action of the two nut segments 1 a, 1b, the nut segments 1 a, 1 b are seated so as move or glide on bolts 7a, 7 b that extend at a right angle relative to the separation plane T.For this purpose, the bolt 7 a is seated so as to be movable inlongitudinal direction in bores 10 a of the nut segments that arealigned with each other and the bolt 7 b is seated so as to be movablein longitudinal direction in bores 10 b of the nut segments that arealigned with each other. Coil springs 15 are supported against the endsof the bolts 7 a, 7 b and are supported, relative to the separationplane T, on an axial surface at the bottom of the respective bores 10 a,10 b. The axial surface can be a shoulder of the two-step bore 10 a, 10b in this embodiment. Each one of the two bolts 7 a, 7 b is provided inthe area of its two ends with such a spring 15 surrounding the bolt. Theresults of this arrangement of the springs 15 is a permanent pretensionof the nut segments 1 a, 1 b in the closing direction. In contrast tothe open position illustrated in FIGS. 1-3, the segments 1 a, 1 b as aresult of the action of the springs 15 are usually closed, i.e., theyeither abut each other in the separating plane T with their flat sides17 or they have only a minimal spacing relative to each other.

The jaws 1 a, 1 b that are thus spring-loaded into the closed positioncan be moved away from each other by hand by means of the actuationdevice 20, i.e., against the spring force, until the inner threadsegments 2 a, 2 b formed on the segments 1 a, 1 b no longer engage bypositive fit the outer thread on which the nut is seated.

The actuation device 20 is designed in this embodiment as a spreadingdevice and is comprised of two levers 21, 22 that are connected to eachother by an articulation 23. The articulation 23, as can be seen in FIG.3, is arranged in the separating plane T of the two nut segments. Thelevers 21, 22 connected by the articulation 23 form a pliers-likeactuating element with two actuation grips 21 a, 22 a that are angledrelative to each other and point outwardly as well as lever sectionsthat are projecting past the articulation 23 and end pivotably inbearings 31, 32 in the nut segments. The rotary bearing 31 of the firstlever 21 is positioned at the symmetry center of the segments 1 a, therotary bearing 32 of the second lever 22 is located at the symmetrycenter of the segment 1 b.

When upon manual actuation by the operator the V-shaped actuating grips21 a, 22 a are moved toward each other, this causes by means of therotary bearings 23, 31, 32 a movement of the segments 1 a, 1 b away fromeach other and thus causes a release of the positive locking actionrelative to the threaded bolt. As soon as the actuating grips 21 a, 22 aof the actuating device are released, the nut segments 1 a, 1 b areclosed again by the action of the springs 15 and engage with positivefit the threaded bolt so that the segmented nut is positionally securedon the threaded bolt.

FIG. 2 shows that the segmented nut for an improved centering action onthe respective support is conically designed on its bottom side, i.e.,on the side that is facing away from the actuating device 20. The bottomside is in the form of a flat truncated cone wherein the conical surface33 is arranged with one half on one nut segment and with the other halfon the other nut segment.

In the second embodiment according to FIGS. 4-7, the two segments 1 a, 1b are also guided relative to each other by means of bolts 7 a, 7 b,wherein the bolt 7 a is positioned on one side of the screw connection(i.e., the inner thread of the nut provided to form the screwconnection) and the other bolt 7 b on the other side of the screwconnection so that the nut segments are moveable relative to each otherin parallel toward and away from each other.

Each bolt 7 a, 7 b is surrounded at its central longitudinal section bya pressure spring 45 that is embodied as a coil spring. The ends of thepressure spring 45 are each supported on the axial surfaces of the firstnut segment 1 a and the second segment 1 b. As a result of this, apermanent loading of the nut segments 1 a, 1 b in the opening directionis caused by the pretension of the pressure springs 45. This is adifference to the afore described first embodiment in which the springsload the two jaws in the closing direction.

In the embodiment according to FIGS. 4-7 the actuating device 20 isembodied as a locking device. The segments 1 a, 1 b are locked in theirclosed position with pretension of the springs 45. This locking actionis releasable by a single push onto a pushbutton 49 a wherein under theforce of the released springs the nut segments move away from eachother, i.e., they open.

A component of the actuating device 20 is a transverse passage 46 whichis provided in only one of the nut segments 1 a and intersects at aright angle the bores 10 a, 10 b in which the bolts 7 a, 7 b that guidethe segments 1 a, 1 b relative to each other are positioned.

The transverse passage 46 receives two locking pins 47 as a furthercomponent of the actuating device 20 that are slidably arranged in thepassage 46 and are configured to lock or arrest the respective bolt 7 a,7 b. For this purpose, each bolt 7 a, 7 b is provided on its outersurface with a recess 48 or a step that is engaged in the locked stateby the respective locking pin 47 by positive fit. The recess 48 extendsin a ramp shape, as illustrated in FIG. 6.

The two locking pins 47 with regard to their longitudinal movability inthe transverse passage 46 are lockable by engagement of a common lockingelement 49 that is arranged centrally between the bolts and is movablyarranged in the nut segment 1 a in a direction transverse to the lockingpins 47. The locking element 49 is also a component of the actuatingdevice.

The locking element 49 is designed like a bolt and has across its lengthmembers 51, 52 of different cross-sectional size. A first member 51 of alarger cross-section size is adjoined by a second member 52 of a smallersized cross-section. The smaller sized member 52 serves as a releasesection. Externally, i.e., outside of the nut segment 1 a, the lockingelement 49 is extended to form a pushbutton 49 a. The pushbutton 49 a islocated on the side of the nut segment 1 a that is facing away from thecone 33.

The nut according to FIGS. 4-7 is closed about a threaded bolt in thatthe segments 1 a, 1 b are moved by hand toward each other until alocking action of the bolts 7 a, 7 b on the locking pins 47 occurs. Inthis locked position the locking pins 47, in turn, are secured inlongitudinal direction by axial support on the member 51 of largercross-section of the locking element 49.

For a quick release of the nut, by applying pressure with the thumb, forexample, the pushbutton 49 a of the locking element 49 is pushed towardthe nut segment 1 a so that the locking element 49 is displaced and theother member 52, serving as a release section, now releases the lockingpins 47 supported on the member 51. They move toward each other andtheir respective opposite ends release the bolts 7 a, 7 b. The releasemovement of the locking pins 47 is assisted by the ramps provided at therecesses 48. Under the action of the springs 45 the nut opens, i.e., itsprings open.

In both embodiments an anchoring means for a fastening element, such asan eyelet or ring member, can be provided on the semi-circular outersurface 4 of the segments 1 a, 1 b. In the vicinity of a hydraulic screwtension cylinder which is to be prevented from flying off when actuated,the nut is attached to the screw bolt arranged adjacent to it in thecircumferential direction. A belt that is connected to the eyelet orring serves as a securing belt. For sufficient positional securingaction of this securing belt it is therefore not required to first screwon the nut by many turns onto the outer thread of the neighboring screwbolt. Instead, the nut is simply opened, in the open state is pushed inlongitudinal direction onto the existing thread, and is then closed. Inreverse order, for releasing the nut, only a single actuation action isrequired, i.e., in the first case spreading apart the segments 1 a, 1 band in the second case applying pressure onto the push button resultingin the two nut segments 1 a, 1 b springing apart.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

1. A nut for screw connections, the nut comprising: two substantiallyidentically sized nut segments of a half-shell shape, wherein the nutsegments each have an inner side provided with an inner thread segmentdefining together an inner thread; wherein the nut segments areconnected to each other so as to be moveable toward each other until thenut segments reach a closed position; means for maintaining a closedposition of the nut segments; an actuating device moveably arranged onat least one of the two nut segments for releasing the closed position,wherein the actuating device is adapted to be manually actuated.
 2. Thenut according to claim 1, wherein the means for maintaining the closedposition are springs loading the nut segments in a closing directiontoward the closed position.
 3. The nut according to claim 2, wherein,relative to the inner thread, a first one of the springs and a secondone of the springs are positioned opposite each other.
 4. The nutaccording to claim 3, wherein the springs are coil springs having afirst end and a second end, wherein the nut segments have bores in whichthe coil springs are positioned, wherein the first end of the coilsprings is supported on an axial surface provided on the nut segments,respectively.
 5. The nut according to claim 4, comprising a parallelguiding action for the nut segments, wherein the parallel guiding actioncomprises bolts supported in the nut segments, wherein the coil springsare positioned on the bolts.
 6. The nut according to claim 5, wherein atleast two of the bolts are positioned parallel to each other for guidingthe nut segments in parallel alignment, wherein, relative to the innerthread, the at least two bolts are positioned opposite each other. 7.The nut according to claim 1, wherein the nut segments in the closedposition are loaded by springs and wherein the actuating device is aspreading device that works against the springs.
 8. The nut according toclaim 7, wherein the spreading device is comprised of a first lever anda second lever that are connected to each other by an articulation. 9.The nut according to claim 7, wherein the first lever is connected by afirst rotary bearing to a first one on the two nut segments and thesecond lever is connected by a second rotary bearing to a second one ofthe two nut segments, wherein the first and second rotary bearings arearranged on a symmetry center of the first and second nut segments,respectively.
 10. The nut according to claim 9, wherein the articulationof the spreading device is arranged in a separating plane of the nutsegments.